Order of Operations: Polynomials and ExponentsDate: 9/10/96 at 10:26:25 From: Heidy Man Subject: Polynomials and Exponents I'm stuck on 3*5-4^2, (3*5-4)^2, -6^2*2, (-6*2)^2 . Date: 9/10/96 at 16:40:13 From: Doctor Ana Subject: Re: Polynomials and Exponents These questions are really about order of operations. You need to know what to do first in order to be able to solve them. You should remember from arithmetic that multiplication and division come before addition and subtraction. (A good way to remember that is My Dear Aunt Sally). When we get into exponents, we have to expand the list to tell us what to do first. The first thing we will do is to evaluate anything that is inside of parentheses. (1) 3 x 5 - 4^2 (2) (3 x 5 - 4)^2 = (15-4)^2 = (11)^2 (3) -6^2 x 2 (4) (-6 x 2)^2 = (-12)^2 The next thing we will do is to evaluate all of the exponents. You have to be careful here: in (1) the 4 is the only thing that is squared, in (2) the 11 inside the parentheses is squared, in (3) the 6 is squared and then multiplied by -1 to get the negative sign, and in (4) negative 12 is squared. It is very important to know whether a negative number is going to be squared or not. Unless it is inside of parentheses, it will NOT be squared, and you have to remember to keep it with the number that is negative. After you evaluate all of the numbers that are squared, then you can finish up the multiplication, addition and subtraction to get your answer. The big thing is to do everything inside of the parentheses first. Do all multiplication and division, and all addition and subtraction left-to-right. -Doctor Ana, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/